a.|x-1|=3

=>x-1=3 hoặc x-1=-3

=>x=4 hoăc x=-2

vậy...

b.2x+17=15

=>2x=15-17

=>2x=-2

=>x=-1

vậy...

c.tự giải

d.4x-15=-75-x

=>4x+x=-75+15

=>5x=-60

=>x=-12

vậy...

2.2+(-3)+4+...+(-2011)+2012

=(-3+2)+...+(-2011+2010)+2012 (có 2010 cặp)

=-1.2010+2012

=-2010+2012=2

Ai mún kb vs mink ko

2.

Tổng A có số số hạng  là:2012-2+1=2011(số)

A=[2+(-3)]+....+[2010+(-2011)]+2012

A=(-1)+..+(-1)+2012

Vậy sẽ có:1005 cặp số

A=[(-1)*1005]+2012

A=(-1005)+2012

A=1007

Nhớ k cho mình nhé

#)Giải :

\(\frac{17}{15}+x=\frac{5}{11}+\frac{17}{11}\)

\(\frac{17}{15}+x=2\)

\(\Rightarrow x=\frac{13}{15}\)

\(\frac{17}{15}+x=\frac{5}{11}+\frac{17}{11}\)

\(\Rightarrow\frac{17}{15}+x=2\left(\frac{5}{11}+\frac{17}{11}=\frac{22}{11}=2\right)\)

\(\Rightarrow x=2-\frac{17}{15}\)

\(\Rightarrow x=\frac{30}{15}-\frac{17}{15}\)

\(\Rightarrow x=\frac{13}{15}\)

Ta có : \(\frac{17}{15}+x=\frac{5}{11}+\frac{17}{11}\)

     \(\Leftrightarrow\frac{17}{15}+x=\frac{22}{11}\)

     \(\Leftrightarrow\frac{17}{15}+x=2\)

     \(\Leftrightarrow x=2-\frac{17}{15}\)

     \(\Leftrightarrow x=2-\frac{17}{15}\)

      \(\Leftrightarrow x=\frac{13}{15}\)

\(5.\left(x-7\right)-4.\left(x+3\right)=-31\)

\(5x-35-\left(4x+12\right)=-31\)

\(5x-35-4x-12=-31\)

\(5x-4x=-31+35+12\)

\(x=16\in Z\)

VẬY \(x=16\)

  5.(x-7)-4.(x+3)=-31

=> 5x-35-4x-12= -31

=> 5x-4x           = -31 + 35 + 12

=> x                   = 16

Vậy x=16

a) 5(x-7)- 4(x+3) = -31

<=> 5x - 35 - ( 4x + 12 ) = -31

<=> 5x - 35 - 4x - 12 = -31 

<=> 5x - 4x = -31 + 35 + 12

<=> x = 16

Vậy x = 16

a)

 \(\left(2x-15\right)^5=\left(2x-15\right)^3\\ \Leftrightarrow\left(2x-15\right)^5-\left(2x-15\right)^3=0\\ \Leftrightarrow\left(2x-15\right)^3.\left[\left(2x-15\right)^2-1\right]=0\\ \Leftrightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15-1\right).\left(2d-15+1\right)=0\end{matrix}\right.\\\Leftrightarrow\left[{}\begin{matrix}2x-15=0\\2x-16=0\\2x-14=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\x=8\\x=7\end{matrix}\right. \)

b) \(\left(7x-11\right)^3=\left(-3\right)^2.15+208\\ \Leftrightarrow\left(7x-11\right)^3=343=7^3\\ \Leftrightarrow7x-11=7\\ \Leftrightarrow x=\dfrac{18}{7}\)

\(A=2\dfrac{3}{13}\times\dfrac{13}{58}\times8\times2\dfrac{15}{24}\times\dfrac{8}{21}\)

\(A=\dfrac{29}{13}\times\dfrac{13}{58}\times8\times\dfrac{21}{8}\times\dfrac{8}{21}\)

\(A=\dfrac{29\times13\times8\times21\times8}{13\times58\times8\times21}\)

\(A=\dfrac{1\times1\times1\times1\times8}{1\times2\times1\times1}\)

\(A=\dfrac{8}{2}\)

\(A=4\)

\(A=\dfrac{29}{13}\cdot\dfrac{13}{58}\cdot8\cdot\dfrac{21}{8}\cdot\dfrac{8}{21}=\dfrac{1}{2}\cdot8=4\)

Chắc là mình không thể giúp gì được cho bạn